Lecture 6

Question 1

all vertebrates have what types of muscles?

Answer 1

1. skeletal
2. cardiac
3. smooth

Question 2

skeletal, cardiac and smooth muscles are derived from ——-

Answer 2

mesoderm

Question 3

what is rule #1 about muscle phylogeny?

Answer 3

muscles and skeleton go together <3

Question 4

the facial muscles, platysma, attaches where?

Answer 4

not to the skeleton but to the skin

Question 5

you only find platysma where?

Answer 5

mammals

Question 6

platysma is derived from what muscle in the shark and salamander?

Answer 6

levator hyomandibulae

Question 7

Muscles attach to bones via what?

Answer 7

tendons

Question 8

muscles attack to bone via ——

Answer 8

tendons

Question 9

muscles are found in———— pairs

Answer 9

antagonistic

Question 10

there are two quite distinct developmen patterns within the body:

Answer 10

1. Muscle in trunks and limbs are derived from somites

2. Muscle in head and pharyngeal arches from somitomeres.

Question 11

How can we tell epaxial from hypaxial muscle groups in adult amniotes?

Answer 11

by their nervous innervation.

Question 12

what is rule #2 about muscle phylogeny?

Answer 12

nerve supply is very useful to identify embryonic origin of a muscle.

Question 13

what is rule #3 about muscle phylogeny?

Answer 13

when it comes to brnachiomeric muscles, there is lots of muscles and therefore lots of evolution

Question 14

why add muscles to support the pectoral girdle?

Answer 14

because the pectoral girdle is not fused to the vertebral column.

Question 15

Salatory (jumping) mode:

Answer 15

big emphasis on axial (dorsal trunk) and hind limb muscles.

Question 16

Cursial mode:

Answer 16

Big emphasis on girdle and limb muscles. They keep limb muscles proximal to body to reduce weight of limbs. Use tendons to lengthen lever (long legs) and finally reduce number of digits to increase speed.

Question 17

Flight Mode:

Answer 17

Big emphasis on pectoral muscles and attachment points. The down stroke always generates lift. Additionally, want to lighten and fuse skeleton wherever possible.

Question 18

what is rule #4 in muscle phylogeny?

Answer 18

appendicular muscles have been extensively remodeled during evolution to support a variety of locomotory styles. Ex.) if there is one muscle in necturus look for 2 or even 4 in a cat.